Product Overview
Phosphoric Acid 75% (CAS 7664-38-2) is a clear, colorless, viscous liquid acid offered in pack sizes from 1 quart bottles to 330 gallon totes. It is a triprotic mineral acid — it can donate three protons — which is what makes it a workhorse for pH adjustment, metal surface treatment, and phosphate chemistry. Water-treatment operators, metal-finishing shops, fertilizer producers, and chemical manufacturers are the buyers who specify this concentration most often.
Alliance Chemical is a distributor, not a manufacturer. Our job is sourcing, packaging, documentation, and DOT-compliant hazmat shipping of this Class 8 corrosive from our Taylor, Texas warehouse. Every claim on this page is limited to what we can support from the product's published data and its governed transport classification.
Why This Concentration
75% sits deliberately between dilute rust-removal strengths and full-strength concentrated acid. You get most of the acid strength of the concentrated product with lower viscosity and easier metering — 85% phosphoric acid is noticeably thicker and slower to pump, especially in cold weather. For large-scale pH adjustment and general metal treatment, 75% is usually the practical choice: strong enough to keep dosing volumes down, fluid enough to handle without heated lines.
Pick a different strength when the job calls for it. For rust removal and surface prep where a milder working solution is the point, start with Phosphoric Acid 30%. If your process is water-sensitive and every extra point of water content matters, or your spec calls for a defined analytical grade, look at Phosphoric Acid 85% ACS Grade. Buyers in food and beverage workflows typically specify Phosphoric Acid 85% Food Grade instead of this product.
Chemical Profile
Phosphoric Acid 75% is a clear, colorless viscous liquid with no odor. The formula is H3PO4 with a molecular weight of 97.995, CAS number 7664-38-2. Density of the 75% solution is approximately 1.575 at 25 °C — a full drum weighs substantially more than the same drum of water, which matters for pallet loading and rack limits. The acid is miscible with water in all proportions, and vapor pressure is low, so the practical exposure hazard is liquid contact rather than vapor. It carries the signal word Danger: it causes severe skin burns and eye damage and may be corrosive to metals (per the product's GHS classification).
Industrial Applications
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pH adjustment (water treatment): Phosphoric acid lowers pH in treatment processes where operators want a moderately strong acid with predictable triprotic buffering behavior rather than the aggressive response of a strong monoprotic acid.
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Metal treatment and etching: Used to clean and etch metal surfaces and to lay down phosphate conversion coatings ahead of painting or coating. Plating and finishing shops run it in cleaning and pickling baths.
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Fertilizer production: A core feedstock for phosphate fertilizers, where the acid supplies the phosphorus that ends up in the finished nutrient product.
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Chemical synthesis: Acts as an acid reagent and phosphate source in the manufacture of downstream phosphate chemicals.
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Acidity regulation in food processing: Phosphoric acid is widely used as an acidity regulator in the food industry; buyers in those workflows generally specify the food grade product linked above rather than this listing.
Handling & Storage
Treat this material as what its label says it is: signal word Danger, causes severe skin burns and eye damage (H314), and may be corrosive to metals (H290) (per the product's GHS classification). Acid-resistant gloves and goggles are the baseline PPE before you break a seal; add a face shield and apron for drum and tote transfers, where splash risk is highest.
Store it cool, dry, and ventilated, in compatible containers — HDPE or glass hold up well; unprotected metal fittings and racks do not, per H290. Keep it away from strong bases and oxidizing agents. Its low vapor pressure means it does not fume aggressively at room temperature, but ventilation in the storage area is still standard practice. Because a filled container is roughly 1.575 times the weight of water, verify your shelf and secondary-containment ratings before stacking drums. The shipping and handling guidance on this page is reviewed by Andre Taki, DOT Hazmat Specialist.
Hazmat & Shipping
This product ships as a regulated hazardous material. It moves under UN1805, proper shipping name "Phosphoric acid solution," Hazard Class 8 (corrosive), Packing Group III (per 49 CFR 172.101). That classification governs how we package, mark, and document every shipment, and it is the basis carriers use when they rate hazmat freight and any accessorial fees they charge — quarts and gallons move as fully marked Class 8 parcels, while drums and totes move as hazmat freight on pallets. Receiving teams should expect Class 8 markings and handle drums and totes with equipment rated for the weight.
Documentation
A Safety Data Sheet is included with every order, available in English, Spanish, French, and Japanese — useful for multilingual crews and for shipments crossing language requirements. A technical data sheet is available for spec review before you buy, and a lot-specific Certificate of Analysis is available with your shipment, so your QC lead can qualify the material against the actual lot fast instead of relying on typical values.
Why Buy from Alliance Chemical
We offer Phosphoric Acid 75% across the full packaging range a buyer actually uses — 1 quart and 1 gallon containers for bench and pilot work, 5, 15, and 55 gallon drums for production, and 275 and 330 gallon IBC totes for bulk consumption — each shipped under its governed UN1805 Class 8 classification with the SDS in four languages and a lot-specific COA. One supplier covers your trial order and your tote program, so scaling up doesn't mean requalifying a source.
Alliance Chemical has operated since 1998 and has served 50,000+ customers from our Taylor, Texas warehouse. We handle corrosives like this every working day; that operating history — not marketing copy — is why buyers keep their phosphoric acid supply with us. Content on this page is reviewed by Andre Taki, DOT Hazmat Specialist.
